Interpretive Summary: During the past several years many intervention strategies have been developed to help increase the resistance of poultry to colonization by Salmonella. Most of the research has focused upon the types of Salmonella that cause human illness. A competitive exclusion culture developed in our laboratory (CF3**TM) has been shown to protect chickens against these types of Salmonella. Salmonella gallinarum however is a type of Salmonella that causes illness and death in chicks during the first ten-days after hatching, and in many countries around the world causes significant economic loses to the poultry industry. Because of the success that we have had with CF3**TM in controlling Salmonella that cause human illness we conducted studies to evaluate the ability of the culture to control Salmonella that cause illness in chickens. In our studies chicks that were infected with Salmonella gallinarum suffered a mortality rate of 73%, however chicks infected with the culture and provided CF3**TM had a mortality rate of only 7.5%. Chicks that were exposed to other chicks infected with Salmonella gallinarum suffered a mortality rate of 48%, however if treated with CF3**TM this was decreased to 4%. This research indicates that CF3**TM can protect chicks against Salmonella that causes illness in chickens as well as humans. This information is important to the poultry industry in countries where the presence of this type of Salmonella causes large economic losses, and may provide poultry producers in these countries a method of decreasing these losses.

Technical Abstract:
A competitive exclusion culture (CF3**TM) was evaluated for its ability to decrease horizontal transmission and chick mortality during the first ten days of production due to the causative agent of fowl typhoid, Salmonella gallinarum. Four separate trials were performed utilizing CF3**TM per manufacturers recommendations. CF3**TM significantly (P < .05) reduced mortality in all four trials compared to untreated control chicks. Mortality for control chicks infected with 10**5 S. gallinarum (seeders) averaged across all four experiments was 74%, compared to 7.5% for the CF3**TM treated seeder chicks. Mortality for control chicks exposed to seeder chicks (contacts) was 47.5%, compared to 3.7% for the CF3**TM treated contact chicks. Surviving contact chicks in the control group averaged 26% S. gallinarum-positive cecal contents and 14% S. gallinarum- positive liver/spleen compared to 2.5% and 1.2% S. gallinarum-positive cecal content and liver/spleen for the CF3**TM treated contact chicks. These results are of importance to the poultry industry in geographical areas where poultry production is negatively affected by fowl typhoid and indicates that treating newly-hatched chicks with CF3**TM may be a novel way of decreasing economic losses associated with this virulent pathogen.